Diagnostic support for skins and inspection method of skin

ABSTRACT

A diagnostic support for a skin includes a radio-transparent structure that defines a folding surface of the skin and on which the skin may be stretched and consequently folded, thereby defining folded, mutually superimposed portions spaced apart from each other. The support may be used for radiographic inspection of a folded animal skin.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Stage Filing based on and claiming priority from International Application No. PCT/162017/052619, filed May 5, 2017, which claims priority from Italian Patent Application Nos. UA2016A003175, filed May 5, 2016, and UA2016A003360, filed May 11, 2016, each of which is incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a diagnostic support for skins and a method of skin inspection. In particular, the present invention relates to a support and a method allowing an acquisition which facilitates the identification of defects in skins, and in particular in leather.

BACKGROUND

As is known, skins of animals usually selected from cattle, sheep, goats, pigs, horses, and more rarely deer, kangaroos, or ostriches are often used for the production of car upholstery, upholstered furniture, clothing, shoes, and many other items. Preferably, the animals used are selected from cattle and horses. The skins, prior to cutting, and therefore prior to the manufacture of the object, are subjected to an analysis process to identify possible defects that, if not removed, could cause major imperfections in the object. Therefore, before processing, an inspector visually checks and marks the defects on the skin with a color that, by being read by a camera, allows a computer to easily locate the defects present on the skin.

The above mentioned prior art has a few major drawbacks. A first major drawback is that the inspector, despite care and accuracy, is not able to detect all the defects or to properly evaluate their extent, leading to the discarding of skins erroneously judged non-compliant or to the approval of skins that, instead, should be discarded. Another major drawback is the impossibility of having a uniformity of judgment due to fatigue of the inspector and non-uniformity of judgment among the various inspectors. In fact, an important drawback is that, once the image has been obtained, it is very difficult to accurately locate the defects in the skin found in the acquired image, which results in cutting portions that are much larger than the defect. Thus, a drawback is that these discarded parts increase the final price of the manufacturing, and therefore of the purchased skins. A further drawback is the use of non-compliant skins, with consequent manufacture of low quality products.

SUMMARY

In this context, the technical task of one embodiment of the present invention is to devise a diagnostic support for skins and a method of skin inspection, which are capable of substantially obviating the above-mentioned drawbacks. Within the scope of this technical task, a major object of one embodiment of the invention is to obtain an inspection method and a diagnostic support, which make it possible to identify and evaluate all the skin defects in a simple and quick manner. An object of one embodiment of the invention is to provide a method and a support that minimize the discarded parts of the skin and therefore reduce the overall costs and the wastage of skins.

BRIEF DESCRIPTION OF THE DRAWINGS

The various embodiments of the invention will now be described in the following detailed description, with reference to the attached drawings, in which:

FIG. 1a shows a diagnostic support for skins according to an embodiment of the present invention;

FIG. 1b shows the use of the diagnostic support of FIG. 1 a;

FIG. 2 shows a further diagnostic support for skins according to an embodiment of the present invention;

FIGS. 3a-3c show a further example of a diagnostic support for skins according to an embodiment of the present invention;

FIGS. 4a-4b show a further diagnostic support for skins according to an embodiment of the present invention; and

FIG. 5 shows a diagram of the method for inspecting a skin according to an embodiment of the present invention.

DETAILED DESCRIPTION

In this document, the measures, values, shapes and geometric references (such as perpendicularity and parallelism), when associated with words like “about” or other similar terms such as “almost” or “substantially,” are to be understood to the extent of measurement errors or inaccuracies due to production and/or manufacturing defects and, especially, to the extent of a slight difference from the value, the measure, the shape, or the geometric reference with which it is associated. For example, these terms, if associated with a value, preferably indicate a difference not exceeding 10% of the value itself.

Furthermore, when used, terms such as “first,” “second,” “higher,” “lower,” “main,” and “secondary” do not necessarily identify an order, a priority relationship, or a relative position, but can simply be used to distinguish more clearly the different components from each other.

Unless otherwise specified, as is apparent from the following discussion, terms such as “treatment,” “data processing,” “determination,” “calculation,” or the like, are understood to refer to the action and/or processes of a computer or similar electronic computing device which manipulates and/or transforms data represented as physical, such as electronic sizes of registers of a computer system and/or memories, into other data similarly represented as physical quantities in computer systems, registers or other storage, transmission or information display devices.

With reference to the aforementioned figures, the diagnostic support for skins according to the invention is designated as a whole by the reference numeral 1 and is adapted to allow the execution of an inspection of a skin 1 a in an inspection apparatus. The skin 1 a is from an animal suitably selected from cattle, sheep, goats, pigs or horses. When stretched, it may have a width at least equal to 2 m and, on average, of at least about 3 m. The skin 1 a, when stretched, defines an exposed surface, a support surface of the skin 1 a opposite to the exposed surface, and a lateral surface defining the profile/perimeter of the skin 1 a and connecting the exposed surface to the support surface.

The inspection apparatus comprises an imaging device 10 adapted to image the skin 1 a stretched and/or folded by the diagnostic support 1 described below. The term “imaging” identifies an image, which is three-dimensional or two-dimensional and reproduces at least the internal structure of the skin 1 a not visible from the outside. The imaging device 10 can be radiological, i.e. adapted to provide a radiological (radiographic, fluoroscopic, or tomographic) image, and precisely a tomographic device adapted to provide a tomography of the skin 1 a.

An example of the imaging device 10 is described in WO2015/112425, hereby incorporated by reference, in paragraphs [0009]-[0092] and in FIGS. 1-8. Another example is presented in WO2016/009316, hereby incorporated by reference, from page 2, line 8 to page 59, line 23 and in FIG. 1a -5.

Imaging device 10, as shown in FIG. 1b , defines an emission axis 10 a and an FOV 10 b (acronym for “Field Of View,” the visual field) identifying the acquisition field of the device 10. The FOV 10 b defines an isocentre, i.e. an axis suitably substantially perpendicular to the emission axis and along which the FOV 10 b extends, preferably in a barycentric position. The FOV 10 b usually has a cylindrical shape with the isocentre as its axis. It can extend to the skin 1 a and in detail it can have a diameter of less than the width of the skin 1 a when stretched, i.e. flat. Precisely, the diameter of the FOV 10 b is substantially less than 1.5 m, in detail less than 1 m, in detail less than 0.7, m and preferably substantially comprised between 0.3 m and 0.4 m.

The imaging device 10 may comprise a source 11 adapted to emit (preferably X-rays) along the emission axis 10 a conveniently perpendicular and incident to the isocentre and a detector 12 adapted to perform one or more acquisitions of the skin 1 a by receiving said emission after it has crossed the FOV 10 b, and therefore at least part of the diagnostic support 1 and of the skin 1 a. The imaging device 10 may comprise a rotating member that is adapted to simultaneously rotate the source 11 and the detector 12 around the FOV 10 b, defining a rotation axis substantially coincident with the isocentre, and a reconstruction unit capable of imaging according to said acquisitions. The imaging device 10 may comprise a gantry 13 enclosing the FOV 10 b and defining a volume for housing the source 11, the detector 12, and suitably the rotating member. As an alternative to the gantry 13, the device 10 can provide a known C-arm.

Additionally, the imaging device 10 may comprise a moving apparatus adapted to translate the gantry 13 or the C-arm along the isocentre. The inspection apparatus may comprise at least one recording unit adapted to provide an image of the skin surface 1 a, i.e. an image reproducing substantially the sole outer profile of the skin 1 a. The recording unit and the imaging device 10 may image the skin 1 a at the same time and/or at different times. The recording unit is adapted to provide an image of the skin 1 a stretched and/or folded by the diagnostic support 1 described below. It is suitable to record at least part of the exposed surface, and preferably the entire exposed surface, with the recording axis suitably almost perpendicular to the exposed surface. The recording unit may provide an optical image of the skin 1 a and therefore comprise at least one camera. Alternatively, it may comprise one or more laser scanner sensors (also called 3D lasers) adapted to detect the three-dimensional pattern of the skin 1 a.

The inspection apparatus may comprise an evaluation module adapted to allow inspection of the skin 1 a based on the imaging and the superficial image. The evaluation module is in data connection with the imaging device and the recording unit so as to receive the images obtained therefrom. It can comprise a control board adapted to analyze the images and, suitably, a screen designed to display the results of the inspection. The evaluation module can comprise a memory comprising several acquired images and a defects database, described below, for each skin 1 a.

The inspection apparatus may comprise at least one marker suitable to be bonded to the skin 1 a conveniently at the exposed surface. The inspection apparatus may comprise at least two markers and, in detail, three markers. The marker can be optical, i.e. visible to an optical camera, or radio-opaque, i.e. visible during the radiological acquisition, or thermal and therefore visible with a thermographic camera.

In order to be visible in the superficial image, the marker can be of the optical type (for example colored differently from the skin 1 a) so as to be visible in the optical image. Alternatively, the marker may have a peculiar thickness easily identifiable through the laser scanner. In order to be visible by imaging, the marker may have a different absorption behavior in the imaging with respect to the skin 1 a. It can therefore be radio-opaque or alternatively radio-transparent and for example identifiable in a hole made in the skin 1 a and preferably characterized by a peculiar section.

Preferably, the marker is both optical and radio-opaque and thus visible in the imaging as well as in the superficial image. It may have a peculiar shape/profile easily identified both in the imaging and in the superficial image, and therefore be innovatively used for reference between the imaging and the superficial image as described below. In some cases, the marker may comprise a chessboard alternating radio-transparent elements recordable, preferably exclusively, by an optical camera, and radio-opaque elements recordable by an imaging device and suitably by an optical camera.

Finally, the inspection apparatus may comprise a device for removing the defects from the skin 1 a, for example by cutting the skin 1 a.

The imaging device and the recording unit, the at least one marker, and, if present, the removal device can be structurally mutually associated so as to uniquely define a position relative to each other, and preferably allow the apparatus to acquire images, inspect the skin 1 a, and possibly remove the defects without moving the skin 1 a.

The diagnostic support 1 is adapted to be at least partially included in the FOV 10 b, i.e. between the source 11 and the detector 12. The diagnostic support 1 may comprise a radio-transparent structure 2 defining a longitudinal axis 2 a and suitable to be introduced in the FOV 10 b by placing the longitudinal axis 2 a preferably substantially parallel and, in detail, coincident with the isocentre. The radio-transparent structure 2 is adapted to fold a skin 1 a so that it takes on a size smaller than the diameter of the FOV 10 b and is thus at least partly included in the FOV 10 b. In detail, it is designed to fold the skin 1 a, thus defining folded portions of the skin 1 a normally superimposed along the longitudinal axis 2 a. More in detail, the structure 2 is suitable to position itself between the folded portions of the skin 1 a, thus spacing the folded portions apart, preferably at the same distance from each other. The folded portions can therefore be superimposed along the emission axis 10 a.

The radio-transparent structure 2 is adapted to define at least one folding surface 2 b of the skin 1 a suitably designed to position itself between the folded portions, thus spacing them apart, preferably at the same distance from each other. The at least one folding surface 2 b is adapted to fold the skin 1 a defining a radius of curvature substantially equal to at least 5 cm, and in detail equal to 10 cm, so as to avoid the formation of folds or other defects on the skin 1 a. It extends substantially parallel to the longitudinal axis 2 a.

A few preferred embodiments of a radio-transparent structure 2 are described below in a non-limiting way. A first preferred embodiment of the radio-transparent structure 2 defining a single folding surface 2 b is shown in FIGS. 1a and 1 b. This structure 2 comprises a flexible plate 21 defining the folding surface 2 b. The flexible plate 21 is adapted to allow at least part of the skin 1 a, and more precisely the entire skin 1 a, to be placed on said folding surface 2 b and to curl up on itself around the longitudinal axis 2 a, thus folding the skin 1 a into a spiral shape and positioning itself between the folded portions. The flexible plate 21 has a thickness, calculated perpendicular to the folding surface 2 b, which is substantially constant, and in detail substantially equal to 0.5 cm. The folding surface 2 b, and thus the flexible plate 21, have a length, measured along the longitudinal axis 2 a, at least equal to 2 m, and precisely equal to 3 m. The folding surface 2 b, and thus the flexible plate 21, have a width, calculated perpendicular to the longitudinal axis 2 a, at least equal to 2 m, and precisely equal to 3 m.

The plate 21 is made of a radio-transparent material such as polyurethane foam. In this first preferred embodiment, the radio-transparent structure 2 may comprise a base body 22 on which the plate 21 (see FIG. 1b ), and thus the skin 1 a, is wound, defining an axis substantially extending almost parallel to the longitudinal axis 2 a. The base body 22 is made of a radio-transparent material such as polyurethane foam. It is integral with the flexible plate 21 at one of its edges parallel to the longitudinal axis 2 a. Preferably, the base body 22 and the flexible plate 21 are bonded to each other by placing the surface 2 b substantially tangent to the outer surface of the base body 22. More preferably, the structure 2 defines a channel 2 c to fit the skin 1 a between the base body 22 and the plate 21 parallel to the longitudinal axis 2 a. Conveniently, the base body 22 and the flexible plate 21 are in one piece. The base body 22 has a circular section, perpendicular to the longitudinal axis 2 a, with a diameter suitably at least equal to 5 cm, and in detail equal to 10 cm.

Finally, in this preferred embodiment, the diagnostic support 1 may comprise fastening means, such as one or more elastic bands or clips, adapted to lock the flexible plate 21, and hence the skin 1 a, wound on the base body 22 (FIG. 1b ). The fastening means are made of polyurethane foam or of a radio-transparent material.

In other preferred embodiments, the radio-transparent structure 2 defines several folding surfaces 2 b mutually alternated on opposite sides with respect to a longitudinal plane 2 d crossing the longitudinal axis 2 a and, suitably, the isocentre. Longitudinal plane 2 d can, for example, be parallel (FIGS. 2 and 3 c) or perpendicular (FIG. 4b ) to the gravitational gradient. Alternatively, it may have any inclination with respect to the gravitational gradient.

The folding surfaces 2 b may be axially spaced apart from each other, thereby avoiding mutual contact between the folded portions of the skin 1 a. Advantageously, the folding surfaces 2 b are axially equally spaced apart from each other so that the folded portions of the skin 1 a are equally spaced apart from each other. More advantageously, the folding surfaces 2 b are parallel to each other and axially equally spaced apart so that the folded portions of the skin 1 a are parallel to each other and equally spaced apart from each other. It should be noted that terms such as axially and axial identify, throughout the document, a direction perpendicular to the longitudinal axis 2 a and along the longitudinal plane 2 d.

An example of a radio-transparent structure 2 is shown in FIG. 2 showing a second preferred embodiment. In this case, the radio-transparent structure 2 may comprise sections 23, each of which defines a folding surface 2 b. The sections 23 and the surfaces 2 b are mutually alternated on opposite sides with respect to the longitudinal plane 2 d and axially spaced from each other, thus defining mutually separate folded portions. Advantageously, the sections 23 are axially equally spaced apart. More advantageously, they are equidistant from the longitudinal axis 2 a. The sections 23 may be substantially parallel to the longitudinal axis 2 a. They may have a length, measured along the longitudinal axis 2 a, at least equal to that of the skin 1 a, and in detail equal to 3 m. The sections 23 may have a circular section with a diameter suitably at least equal to 5 cm, and in detail equal to 10 cm. The sections 23 are made of a radio-transparent material such as polyurethane foam. Finally, the diagnostic support 1 may comprise a frame suitable to support the sections 23 and attachable to the imaging device 10.

Another example of a multi-surface 2 b radio-transparent structure 2 is shown in FIGS. 3a-3c showing a third preferred embodiment. In this case, the radio-transparent structure 2 may comprise a plurality of panels 24, preferably six, each defining a folding surface 2 b and suitable to be stacked, thus arranging and folding the skin 1 a. The panels 24 are suitable to be stacked, thereby placing the skin 1 a between adjacent panels 24. Therefore, each panel 24 defines for the skin 1 a at least one support surface 2 e and one folding surface 2 b. In particular, each panel defines two support surfaces 2 e opposite to one another and connected by a single folding surface 2 b. The support surfaces 2 e of the panels 24 are parallel to each other and to the longitudinal axis 2 a. In particular, they are perpendicular to the plane 2 d. It should be noted that the width of the support surfaces 2 e, calculated perpendicular to the plane 2 d, of each panel 24 is inversely proportional to the axial distance of the panel 24 from the longitudinal axis 2 a. The folding surface 2 b may have a curved profile with a radius at least equal to 5 cm, and in detail equal to 10 cm. The panels 24 may have a length, measured along the longitudinal axis 2 a, at least equal to that of the skin 1 a, and in detail equal to 3 m. In order to support the panels 24, the diagnostic support 1 may comprise a support for the radio-transparent structure 2 identifiable, for example, as a known radiological bed.

Another example of a multi-surface 2 b structure 2 is shown in FIGS. 4a-4b showing a fourth preferred embodiment. In this case, the radio-transparent structure 2 comprises a first fork 25 comprising first tines 25 a and a second fork 26 comprising second tines 26 a suitable to position themselves between the first tines 25 a, enabling the skin 1 a to fit between the tines 25 a and 26 a by folding. The tines 25 a and 26 a are substantially parallel to each other. Their thickness, calculated perpendicular to the longitudinal plane 2 d, is even so that the folded portions of the skin 1 a are evenly spaced apart. This thickness is at least equal to 5 cm, and in detail equal to 10 cm. The tines 25 a and 26 a may have a length, measured along the longitudinal axis 2 a, at least equal to that of the skin 1 a, and in detail equal to 3 m. The projecting ends of the tines 25 a and 26 a define the folding surfaces 2 b of the skin 1 a and have a curved profile with a radius at least equal to 5 cm, and in detail equal to 10 cm.

In order to arrange and then fold the skin 1 a between the tines 25 a and 26 a, the diagnostic support 1 may comprise a mover adapted to define a mutual motion of the forks 25 and 26 perpendicular to the longitudinal axis 2 a. The mover defines an insertion position (FIG. 4a ), in which the tines 25 a and 26 a are mutually spaced apart so as to allow the insertion of the skin 1 a between the forks 25 and 26, and a folding position (FIG. 4b ), in which the forks 25 and 26 are close together so as to mutually interpose the tines 25 a and 26 a, thereby folding the skin 1 a. The diagnostic support 1 may comprise a conveyor adapted to move the skin 1 a, arranging it between the tines 25 a and 26 a. The conveyor is identifiable as one or more wires integral with the skin 1 a and adapted to slide between the tines 25 a and 26 a, dragging and, therefore, arranging the skin 1 a between the tines 25 a and 26 a.

Finally, in each of the second, third, and fourth preferred embodiments, the diagnostic support 1 may comprise fastening means capable of bonding any loose flaps of the skin 1 a to the radio-transparent structure 2. The fastening means are made of polyurethane foam or of a radio-transparent material.

The analysis process can be part of a method for inspecting a skin 1 a according to the invention generally designated by the reference numeral 100 and shown schematically in FIG. 5. The method 100 may be carried out by means of said apparatus for inspecting a skin 1 a. It may also be implemented by means of the diagnostic support structurally described above.

Initially, the inspection method 100 may comprise a preparation step 110 wherein one or more of said markers (conveniently three) are associated with the skin 1 a. Briefly, the inspection method 100 may comprise a first acquisition step 120 wherein said skin 1 a is imaged at least once (preferably a radiological image and more preferably a tomography), a second acquisition step 130 wherein at least one superficial, specifically optical image of the skin 1 a is obtained, and a relative orientation step 140 wherein the imaging and the superficial image are spatially cross-referenced so as to relate the points of the imaging to the points of the superficial image, making it possible to identify in the superficial image, and thus in the skin 1 a, the position of a defect detected in the imaging. It should be noted that the first acquisition step 120 and the second acquisition step 130 may be carried out at the same time and/or at different times. The preparation step 110 may precede the acquisition steps 120 and 130 or be interposed between said acquisition steps 120 and 130.

In the first acquisition step 120, the imaging device 10 images at least part and preferably the whole skin 1 a and, if present, the markers. The first acquisition step 120 may comprise, and precisely be carried out by using the diagnostic support 1 structurally described above. Therefore, it may comprise a folding sub-step wherein the skin 1 a is folded so as to reduce the overall dimensions, and in particular the width thereof, a sub-step for inserting at least part of the folded skin 1 a in the FOV 10 b of an imaging device and suitably in an imaging device 10, and an acquisition sub-step wherein the folded skin 1 a is imaged, thereby obtaining an image, in detail a radiological image and more in detail a tomography of the folded skin 1 a.

In the folding sub-step, the skin 1 a, by using the support 1, is folded back on itself, defining folded portions spaced apart, preferably at the same distance from each other. In detail, in the case of the support 1 of FIGS. 1a and 1 b, at least part of the skin 1 a is placed on the folding surface 2 b by arranging the edge of the skin 1 a in the fitting channel 2 c. Preferably, the skin 1 a is completely placed on the folding surface 2 b. At this point, the flexible plate 21 and the skin 1 a are folded on the base body 22, both of them taking on a spiral shape (FIG. 1b ) and separating and suitably spacing evenly apart the folded portions of skin 1 a.

Alternatively, in the case of the diagnostic support 1 of FIG. 2, the skin 1 a is passed through the various sections 23 and rested on folding surfaces 2 b alternated on opposite sides with respect to the longitudinal plane 1 a.

In a further alternative (FIGS. 3a-3c ), the skin 1 a is placed on a support surface 2 e of a first panel 24, folded on the folding surface 2 b of the same first panel 24 and rested on the support surface 2 e of the first panel 24 opposite to the preceding one. Now, a new panel 24 is rested on the skin 1 a by enclosing it between the two panels. The skin 1 a is folded on the folding surface 2 b of the second panel 24 placed on a support surface 2 and the second panel 24. These operations are repeated until the entire skin 1 a is folded on the panels 24.

In another alternative (FIGS. 4a and 4b ), the skin 1 a is positioned between the tines 25 a and 26 a so as to fold, thus defining folded portions separated from each other by the tines 25 a and 26 a, and suitably equally spaced apart. This operation is performed by placing the diagnostic support 1 in the insertion position, arranging the skin 1 a between the forks 25 and 26 and then bringing the diagnostic support 1 in the folding position, i.e. bringing the forks 25 and 26 close together so as to mutually interpose the tines 25 a and 26 a, thus folding the skin 1 a. Alternatively, this operation is performed by the conveyor which slides the skin 1 a between the tines 25 a and 26 a.

Once the folding sub-step is finished, the insertion sub-step takes place, in which at least part of the skin 1 a and of the radio-transparent structure 2 is placed in the FOV 10 b, followed by the acquisition sub-step, wherein one or more acquisitions (for example at different angles) of at least part and suitably of the totality of the folded skin 1 a is/are performed. The acquisition sub-step ends with the imaging, in detail, of a radiological image, and more in detail of a tomography of the folded skin 1 a.

At this point, the first acquisition step 120 may comprise a stretching sub-step, wherein the imaging obtained in the acquisition sub-step is planarized, thus providing imaging of the stretched skin 1 a. This stretching sub-step can be performed by planarizing a first surface, for example an edge, of the imaging of the skin 1 a and replacing the pixels of the imaging on the basis of the coordinates and the distances of the pixels with respect to the first surface.

In the second acquisition step 130, the recording unit acquires a superficial (suitably optical) image of at least part of the skin 1 a, and in detail of the exposed surface. Preferably, a superficial image of the whole exposed surface is obtained. Also a superficial image of the support surface, and in some cases of the lateral surface, may be acquired. The superficial image may comprise the markers. It should be noted that, both in the at least one superficial image and in the imaging, at least part of the perimeter of the skin 1 a can be present.

Once the acquisition steps 120 and 130 are completed, the method 100 comprises the relative orientation step 140. The relative orientation step 140 may comprise a first identification sub-step 141 wherein at least a first discontinuity is detected in the imaging, a second identification sub-step 142 wherein at least a second discontinuity is detected in the superficial image, and a mutual cross-reference sub-step 143 wherein the imaging and the superficial image are mutually spatially referenced so as to relate the points or pixels of the imaging to the points or pixels of the superficial image, thereby allowing a localization of the defects in the skin 1 a, and in particular the identification of the position of an internal defect, i.e. detected in the imaging, in the superficial image and then in the skin 1 a. The term “point,” as used herein, can be intended to mean individual pixels or a plurality of them. Preferably, the term “point” defines a single pixel.

The term “discontinuity” identifies a change in intensity between contiguous pixels greater than a predefined threshold and/or a geometric variation of the skin 1 a in the imaging and/or in the superficial image. In particular, a discontinuity can be identified if the change in intensity between contiguous pixels is at least equal to a threshold of variation between the intensities of contiguous pixels. Such variation is at least equal to 1%, in detail equal to 5% and preferably equal to 10%. Alternatively, a discontinuity can be identified if the intensity of a pixel is less than a minimum acceptability threshold and/or greater than a maximum acceptability threshold. Geometric variation is identifiable in the case in which sudden changes in shape, such as those found at the perimeter of the skin 1 a, or of one or more markers characterized by a peculiar profile/shape, are detected in the imaging and/or in the superficial image. Therefore, a discontinuity can be detected at the profile of the skin 1 a and/or of the markers. Alternatively or additionally, a discontinuity can be detected in the area of one or more defects visible in the imaging (in particular in the radiological image) and in the superficial image. Further alternatively or additionally, a discontinuity can be detected in the area of a hole or other reference specially provided in the skin 1 a before inspection.

After identifying first and second discontinuities, the sub-steps 141 and 142 are concluded and the mutual cross-reference sub-step 143 begins, in which, by causing at least a first discontinuity to coincide with at least a second discontinuity, the imaging and the superficial image are mutually spatially referenced so as to be able to link any point or pixel of the imaging to a point or pixel of the superficial image, and therefore of the skin 1 a. The reference between the imaging and the superficial image is obtainable by causing one or more first discontinuities to match to, and precisely to coincide with, one or more second discontinuities. This operation can be performed by causing the profile of one or more first discontinuities to coincide with the profile of one or more second discontinuities. In particular, first and second discontinuities identifiable at the perimeter of the skin 1 a and/or related to the shape of a marker can be used. Alternatively, reference between the acquired images is obtained by causing the position of two or more first discontinuities of the imaging to coincide with two or more second discontinuities of the superficial image. It should be noted that, for greater precision, these acquired images of a skin 1 a may be mutually referenced by causing both the profile and the position of first and second discontinuities to coincide.

At this point, the mutual cross-reference sub-step 143 and the relative orientation step 140 are concluded and the inspection method 100 may comprise a, preferably automatic, identification step 150, for detecting skin 1 a defects in said skin 1 a on the basis of the first and second discontinuities and/or a step 160 for linking the imaging to the superficial image.

The identification step 150 comprises, initially, a cross-reference sub-step 151 wherein a cross-reference system common to said imaging and to said image is identified and with respect to which the first and second discontinuities can be referred. The reference system can be determined by making use of the first and second discontinuities used in the cross-reference sub-step 143, for instance, by arranging the origin of said reference system at a point common to the first and second discontinuities. In particular, the reference system may have two parallel axes and one axis perpendicular to the exposed surface of the skin 1 a.

Thus, the identification step 150 comprises a localization sub-step 152 in which the coordinates defining the position, and in some cases the shape, of the discontinuities and, therefore, of the defects are determined with respect to the reference system. In this localization sub-step 152, first coordinates defining the position of the first discontinuity in the imaging with respect to the reference system are determined for each first discontinuity, and second coordinates defining the position of the second discontinuity in the superficial image with respect to the reference system are determined for each second discontinuity. Additionally, the first coordinates may define the shape of the first discontinuities, and the second coordinates may define the shape of the second discontinuities. The identification step 150 may comprise a data collection sub-step 153 in which a defects database is created, which links the first and second coordinates to each defect detected in the imaging and in the superficial image as described above. In the linking step 160, the spatial reference between the imaging and the superficial image can be used to generate a composite image of the imaging and the superficial image, which allows the passage, during a visualization, from the imaging to the superficial image or vice versa without changing the orientation of the skin 1 a.

Lastly, the inspection method 100 may comprise a step of removing 170 the detected defects from the skin 1 a on the basis of the first and second coordinates of the defects, and in detail on the basis of the defects database. In this step, the removal can be performed by the removal device which, on the basis of the defects database, is able to automatically locate and remove the defects present in the skin 1 a.

The above described inspection method 100 and specifically the first acquisition step 120 teach a new use of a diagnostic support for folding a skin 1 a on the diagnostic support 1, reducing the width of the skin 1 a to a value that is substantially smaller than the diameter of the FOV 10 b of an imaging device, thereby allowing at least a partial introduction of the skin 1 a, which is folded on the diagnostic support 1, in the FOV 10 b.

This new use of the diagnostic support allows the skin 1 a to be folded, thus defining folded portions of said skin 1 a that are not in contact with each other. In detail, the use of the diagnostic support 1 defines folded portions of the skin 1 a that are equally spaced from one another, and more in detail substantially parallel to each other. The invention provides significant advantages.

A first important advantage is that the diagnostic support 1 and the method 100 allow the execution of an objective analysis of the defects present within the skin, and therefore allow a uniformity of evaluation of the skin 1 a, until now impossible. An important advantage is that the inspection method 100, by spatially cross-referencing the imaging and the superficial image, allows all the defects present on the skin 1 a to be identified in an extremely precise manner. An important advantage is that the cross-referencing of the imaging and the superficial image can be performed without performing any operations (such as dyeing) on the skin 1 a, which until now are normally performed and make some portions of the skin 1 a unusable.

Another advantage is that the inspection method 100 allows the position, size, and shape of all the defects present in the skin 1 a to be identified in a very precise way, thus allowing the reduction of the extent of the skin 1 a to be removed in order to remove the defect. Another advantage lies in the fact that the inspection method 100 minimizes the discarded parts, and therefore the manufacturing price of a skin 1 a.

A no less important advantage is given by the composite image, which allows the passage from the imaging to the superficial image or vice versa without changing the orientation of the skin 1 a. Therefore, the operator may, for example, visualize a defect in the superficial image and switch to the imaging to obtain the depth of the superficially identified defect or, alternatively, locate an internal defect in the imaging and then switch to the superficial image to accurately determine its position.

Another important advantage lies in the fact that the diagnostic support 1, the method, and the use defined thereby allow the overall dimensions of the skin 1 a to be reduced, allowing it to be inserted within an FOV 10 b of any of the imaging devices 10 known to date. A major advantage is also to be found in the fact that the diagnostic support separates the folded portions of the skin 1 a, thus favoring the identification of defects.

The invention is susceptible of variations falling within the scope of the inventive concept, as specified in the independent claims, and of the related technical equivalents. In this context, all details are replaceable by equivalent elements and any type of materials, shapes and dimensions may be present. In particular, in the superimposing sub-step 143, the spatial reference between the imaging and the superficial image can be carried out by using the information relating to the mutual position between the imaging device and surface recording unit. 

The invention claimed is:
 1. A method for inspecting a skin designed to detect defects in said skin, comprising: obtaining a radiological image of said skin, wherein said radiological image comprises a plurality of pixels; storing said radiological image in a memory; obtaining a superficial image of said skin, wherein said superficial image comprises a plurality of pixels and said skin comprises at least one bonded marker that is optical and radio-opaque; storing said superficial image in the memory; and spatially cross-referencing said radiological image and said superficial image, wherein said spatial cross-referencing comprises: retrieving said radiological image from the memory; detecting at least a first discontinuity in said radiological image; retrieving said superficial image from the memory; detecting at least a second discontinuity in said superficial image; and spatially cross-referencing said radiological image and said superficial image by matching at least one of said at least first discontinuity to at least one of said at least second discontinuity.
 2. The method according to claim 1, further comprising: defining a cross-reference system common to said radiological image and to said superficial image with respect to which said first discontinuities and said second discontinuities can be referred; and detecting a location of said defects in said skin on the basis of said first and second discontinuities.
 3. The method according to claim 2, further comprising determining first coordinates of said first discontinuities in said radiological image and second coordinates of said second discontinuities in said superficial image, wherein said determined first coordinates define a position of said defects in said radiological image, and said determined second coordinates define a position of said defects in said superficial image.
 4. The method according to claim 3, further comprising defining a defects database that associates each of said defects in said skin with said first and second coordinates.
 5. The method according to claim 4, wherein said defects database associates a form of said defect to each of said defects and the method further comprises removing said defects from said skin based on said defects database.
 6. The method according to claim 1, wherein said radiological image is obtained using tomography.
 7. A method for inspecting a skin designed to detect defects in said skin, comprising: obtaining a radiological image of said skin, wherein said radiological image comprises a plurality of pixels; storing said radiological image in a memory; obtaining a superficial image of said skin, wherein said superficial image comprises a plurality of pixels; storing said superficial image in the memory; and spatially cross-referencing said radiological image and said superficial image, wherein said spatially cross-referencing comprises: retrieving said radiological image from the memory; detecting at least two first discontinuities in said radiological image; retrieving said superficial image from the memory; detecting at least two second discontinuities in said superficial image; and spatially cross-referencing said radiological image and said superficial image by causing the positions of the at least two first discontinuities to coincide with the positions of the at least two second discontinuities.
 8. The method according to claim 7, further comprising: defining a cross-reference system common to said radiological image and to said superficial image with respect to which said first discontinuities and said second discontinuities can be referred; and detecting a location of said defects in said skin on the basis of said first and second discontinuities.
 9. The method according to claim 8, further comprising determining first coordinates of said first discontinuities in said radiological image and second coordinates of said second discontinuities in said superficial image, wherein said determined first coordinates define a position of said defects in said radiological image, and said determined second coordinates define a position of said defects in said superficial image.
 10. The method according to claim 9, further comprising defining a defects database that associates each of said defects in said skin with said first and second coordinates.
 11. The method according to claim 10, wherein said defects database associates a form of said defect to each of said defects and the method further comprises removing said defects from said skin based on said defects database.
 12. The method according to claim 7, wherein said radiological image is obtained using tomography. 